254 Mr Wilson , On the Hall Effect in Gases 
Table I. 
Pressure 0-30 mm. Current 1*56 x 10 -4 ampere 
Angle 
P.D. 
P.D. 4 - Sine 
Angle 
P.D. 
P.D.-^Sine 
90° 
122 
122 
40° 
75 
117 
o 
OO 
120 
122 
b 
CO 
59 
118 
b 
114 
121 
20° 
39-5 
116 
60° 
103 
119 
10° 
21 
121 
50° 
90 
118 
0° 
3 
— 
Table II. shows the variation of the Hall effect (that is the 
electrometer deflection) with the magnetic field. When measuring 
the Hall effect the field was always reversed and the sum of the 
two deflections obtained taken as the Hall effect due to double 
the field employed. 
The results in Table II. show that the Hall effect is pro- 
portional to the magnetic field. Similar results were obtained at 
other pressures. 
Table II. 
i 
Pressure 456 mm. Current 5*4 x 10 -0 ampere 
Hall Effect 
(Electrometer deflection) 
Magnetic Field 
Ratio 
79 
113 
1-43 
48 
69 
1-44 
24 
35 
1*46 
14 
21 
1-50 
The results in Table III. show that the Hall effect is very 
nearly independent of the current producing the discharge. At 
pressures below one millimetre the range of current which could 
be employed at any one pressure was too small to allow this 
independence to be satisfactorily verified for each pressure 
separately, but the results on the variation of the Hall effect with 
the pressure make it extremely probable that the Hall effect is 
nearly independent of the current at pressures down to 0*26 mm. 
